Increasingly, industries rely on a fleet of dispatched mobile units to provide services or deliver products. For example, general contractors, utility providers, cable companies, appliance service providers, truck rental companies, taxi companies, airlines, police/fire departments, and various delivery services all utilize mobile units (e.g., vans, trucks, automobiles, airplanes) as part of their respective operations. When an operation involves numerous mobile units, it is often desirable, yet difficult, to obtain information about the dispatched mobile units. For example, it is desirable to know where the mobile units are at a given time. Also, the dispatching company may want to know if a mobile unit has been involved in an accident or if an employee driver is using the mobile unit in an inappropriate manner.
Locating a mobile unit is especially useful if it can be done from a remote management station, such as where the scheduling is done. This remote locating process usually entails two steps: determination of the position of the mobile unit, and transmission of the position data to the remote management station. One of the methods for determining the location of a mobile unit utilizes the Global Positioning System (GPS). The GPS involves a plurality of satellites orbiting the earth and sending out, at synchronized times, a code sequence that identifies the satellite. Along with this identification information is sent some positioning information that can be processed to determine a position. A GPS receiver receives the code sequence and the positioning information and passes it on to a processor. The processor determines the position of the GPS receiver by using well-known methods such as triangulation.
The position information as determined by the processor is then transmitted to a server that stores the information. Typically, this transmission from the GPS receiver to the server is achieved via a combination of wireless communication networks such as CDMA and the Internet. Further details of this system are provided in U.S. Pat. No. 5,959,577 (“the '577 patent).
While the system of the '577 patent accomplishes the goal of allowing remote management stations to obtain information about mobile units, it has several drawbacks that make the system unappealing to clients. One of the drawbacks is the lack of flexibility in changing the reporting patterns of the mobile units. The system of the '577 patent provides four modes in which the mobile units can operate, and the mode selection affects how often the mobile unit updates its position information. There is no mention in the '577 patent as to whether a single mobile unit always operates in the same mode or the mode is changeable. Thus, if the fleet management operator decides that he wants to see more frequent updates after the mobile units are dispatched, there is no way for the operator to change the update frequency.
Another drawback is the lack of scalability. Since the central server receives all the information collected by the mobile units and maintains a record of them, the amount of data that is stored becomes very large very fast. Given that each additional mobile unit takes up a lot of space in the database, it is difficult to add many mobile units to the system at once. If a company with a large fleet signs up for the system, the additional burden could cause the system to crash.
A system and method of providing mobile unit information (e.g., position information) in a more flexible and user-friendly manner is desired.